class Calculator(object):
    def _init_(self, number):
     self.number = number
    def _add_(self, other):
     self.number = self.number + other
     return self.number
    def _sub_(self, other):
     self.number = self.number - other
     return self.number
    def _mul_(self, other):
     self.number = self.number * other
     return self.number
    def _truediv_(self, other):
     self.number = self.number / other
     return self.number
    calculator = Calculator(10)
    print(calculator + 5)
    print(calculator - 5)
    print(calculator * 5)
    print(calculator / 5)